The present disclosure relates generally to crystalline forms of the antiviral compound named (1aR,5S,8S,9S,10R,22aR)-5-tert-butyl-N-[(1R,2R)-2-(difluoromethyl)-1-{[(1-methylcyclopropyl)sulfonyl]carbamoyl}cyclopropyl]-9-ethyl-18,18-difluoro-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxamide, processes for making the forms, and their therapeutic methods of use.
The hepatitis C virus (HCV), a member of the hepacivirus genera within the Flaviviridae family, is the leading cause of chronic liver disease worldwide (Boyer, N. et al. J Hepatol. 2000, 32, 98-112). Consequently, a significant focus of current antiviral research is directed toward the development of improved methods for the treatment of chronic HCV infections in humans (Ciesek, S., von Hahn T., and Manns, M P., Clin. Liver Dis., 2011, 15, 597-609; Soriano, V. et al, J. Antimicrob. Chemother., 2011, 66, 1573-1686; Brody, H., Nature Outlook, 2011, 474, S1-S7; Gordon, C. P., et al., J. Med. Chem. 2005, 48, 1-20; Maradpour, D., et al., Nat. Rev. Micro. 2007, 5, 453-463).
There remains a need to develop effective treatments for HCV infections. Suitable compounds for the treatment of HCV infections are disclosed in U.S. Publication No. 2014-0017198, titled “Inhibitors of Hepatitis C Virus” filed on Jul. 2, 2013 including the compound of formula I:

However, Compound I was not heretofore known in any crystalline form.